SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '76b23e78a0133db5c73b7421cebed1cd525046b1ca6d2f787ae16193908a453f' 
  AND token = 'KwQev7D4/0WWpuowHXACcVZRHXoREPVSMRaF1lv0fa4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}